The present invention relates to a novel decapeptide having gonadotropin releasing activity, i.e. corpus luteum hormon (LH) releasing activity and follicle stimulating hormon (FSH) releasing activity.
In 1971, a decapeptide having LH and FSH-releasing activity was isolated from hog hypothalamus and its chemical structure was determined as pGlu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH.sub.2 hereinafter referred to as "LH-RH".
The present inventor has sought a naturally occuring unknown gonadotropin releasing factor whose structures is different from the above LH-RH. As a result of the seek, a novel peptide having gonadotropin releasing activity has been isolated from an extract of chicken hypothalamus and its chemical structure has been dertermined.